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16.12A, is a precision machine tool acquired from Matsushita Panasonic for micro-manufacturing applications. The use of linear motors to drive the slide and tool post results in fast part processing and elimination of thermal distortion. Its use is limited to electrically conductive materials. In ECDM of MMCs, even though the amount of material removed by ECD was found to be much less than that removed by EDE, it still contributes in some measure to the total amount. The machine can perform metal cutting at speeds of up to 12,000 rpm, but without the rotary guide bushing, the cutting speeds can be increase up to 16,000 rpm. The EDM provides an advantage for making stamping tools, wire drawing and extrusion dies, forging dies, header dies, intricate mould cavities, etc. The spindle with air bearing or air turbine rotates with a very high speed of 60,000 rpm. In general, a hole the size of a human hair (about 8 μm in diameter) is about the smallest hole that could be made using conventional machine tools on a production basis. Holepop EDM Supplies and Electrodes is a provider of high precision, customizable components used in electrical discharge machining small hole drilling. It has working tank with a work holding device. Micro-machining CNC centre (A) and exemplary applications: electronics (B), precision five-axis machining (C) and micro-fluidic support plate (D) [25]. Subspindles for drilling and milling work with 10,000 rpm. Heat from What is Electrical Discharge Machining (EDM) Process and How it Works? Depending on the tool shape and geometry, the flushing efficiency varies. These parameters are comparable with those for aluminum and plastics. The optimal adjustment of process parameters can give high surface finish, reduced heat affected zone, and dimensional precision in ECDM process as shown in Fig. Schematic of the ECDM process. Figure 3-1. EDM can cut intricate contours or cavities in pre-hardened steelwithout the need for heat treatment to soften and re-harden them. Electrical Discharge Machining Market Report 2020 Global Industry Size, Segment by Key Companies, Types & Applications and Forecast to 2025 Market Study Report Date: … Micro-scale milling machine tool (A) and three-axis mMT module (B) [19]. The machining center can also be served by a robot in place of the pallet changer. Along with a rigid machine, the spindle must be stable to minimize tool vibration and prevent thermal expansion. The common tool geometries being used are square, rectangular, cylindrical, and circular. It offers a combination of high peak power, high repetition rates and beam quality that makes it suitable for drilling holes as small as 10 µm (0.0004″) diameter in stainless and carbon steels, titanium, ceramics, silicon and other hard materials up to about 1 mm thick. It is widely used, for example, for the production of forging or stamping tools made out of extremely hard metal. 16.5 shows a high-speed, high-precision lathe for the machining of tiny precision parts (Fig. Axis arrangement (A) and a variety of shafts (B) produced on CNC micro-lathes. When a DC voltage is applied to tool and workpiece electrodes, the breakdown of the insulating layer of hydrogen bubbles leads to spark discharge. The result of a single discharge is a crater-shaped pit on the electrodes’ surfaces, the discharge crater (Fig. Finally, the work piece can also be moved by a control unit during the erosion. 16.6 illustrates the principle of the micro-EDM lathe which, from a kinematical point of view, operates similarly to a conventional lathe. This principle of structuring allows the use of every material that is characterized by electric conduction; suitable are, therefore, a wide range of metals and selected semiconductors like silicon [31]. The main areas of application for electrical discharge machining are the manufacture of injection moulds, die casting moulds, forging dies and prototypes. Fig. Micro-EDM machine (A) and magnification of the working space (B) [21]. The use of high frequency generators minimizes the influence on the subsurface and enables a surface roughness down to an arithmetical average peak-to-valley height of Ra=0.1 μm. Figure 16.10. EDM is qualified and used as a repair and maintenance tool even in operating nuclear power plants to solve special problems. The ironless AC linear motors used produce zero cogging torque, reducing disturbance forces in the system and further increasing the dynamic performance of the stages. EB drilling is similar to laser drilling in that energy is created and precisely focused on a workpiece to bring about highly localized melting. Cutting speed is very low. For instance, Fig. A previous study on ECDM of particulate MMCs showed that a relatively high current density is present around the interfaces between the matrix and the particle during the course of the machining26 (Fig. Figure 9.7. Krishna K. Saxena, ... Xichun Luo, in Hybrid Machining, 2018. One is a modular approach with multiply sections for assemblies and the second is a desktop-size factory for producing micro-components. Moreover, the installation of the dust extraction control valve system leads to the production of dust-free PCBs. Moreover, on this base small work cells for three-, four- or five-axis parts can be created. The machine shown in Fig. 16.9 was designed with a C-type concrete made of a special mineral cast in order to maximize the stiffness characteristics and achieve better vibration damping. Figure 16.5. In micro-EDM, the tool geometry solely depends on the microfeature to be generated. 16.5B) with a maximum diameter of 7 mm and length of 40 mm, which allows going down to subminiature parts with 0.5 mm in diameter. Figure 16.11. The most important advantage of the EB drilling process is its ability to produce hundreds to thousands holes, up to 2000 holes per second, quickly. Various processes are possible with electrical discharge machining, including turning, milling, grinding and small hole drilling. 3-2(c)). Depending on the amount of the transferred energy, the thermal exposure of the machined surface also leads to a thermally influenced subsurface zone. Electrical Discharge Machining EDM is the thermal erosion process in which metal is removed by a series of recurring electrical discharges between a cutting tool acting as an electrode and a conductive workpiece, in the presence of a dielectric fluid. Fig. The bubble film blanketing effect causes current density at the tool electrode to exceed a certain critical value, which leads to a discharge between the tool and the surrounding electrolyte. Although, many studies have proposed that gas bubbles at the cathode surface will coalesce into a gas film through which the discharge occurs,23’28 it is considered that the formation of a gas film or layer will depend on the machining conditions, such as electrolyte concentration, temperature and the geometry of the cathode electrode. Such activities involve scaling down some units to handle smaller parts or adding options that can facilitate the micro-manufacturing applications. Complicated 3D micro-structures, micro-grooves and diesel fuel injection nozzle holes of 140 μm diameter have been precisely machined by Laser-assisted electric discharge machining [124–126]. This system has a built-in WEDG unit to process the tool electrode to the desired diameter (or shape) or turn it into micro-shafts by itself, using the electro-discharge principle with reverse polarity. With our wide range of materials and technical support, we can help OEMs and end users achieve the best results. Nowadays, it is used like a conventional machine tool due to … Moreover, most of the previous work on ECDM of non-conductors used a small cathode with a large anode-to-cathode surface ratio (typically over 100) and this undoubtedly would promote the formation of a gas film. S.S. Joshi, D. Marla, in Comprehensive Materials Processing, 2014. The speed at which graphite can be machined is limited only by the performance of the computer and the machining system, but not by the material itself. It is possible to perform four-axis machining using a micro-rotary table or five-axis machining by installing a micro-trunnion table. H. Steiner, in Nuclear Decommissioning, 2012. Several holes per second were drilled, depending on the valve actuator response. 6.61. The voltage used in this machining process is not constant but it is applied in pulse form. In addition, so-called diamond fly cutting can be used for micro-structuring of optical surfaces using four-axis and five-axis milling (Fig. In particular, part handling and fixturing is of significant importance. Electrical discharge machining (EDM) has, for quite some time, been the response for high accuracy and demanding machining applications where regular metal machining is troublesome or unimaginable. During extremely high discharge energies, the influence on the subsurface can reach up to several millimeters into the bulk material. One of these modules, the Advanced Process System, has a built-in vibration sensor in the spindle, together with a spindle diagnostic module. Principle of micro-EDM lathe (A) and its possible applications (B) [14]. Here are some applications of Electrical Discharge Machining: It is used for producing hole size less than 0.1 mm; Used for die sinking or die manufacturing. As a result, it automatically compensates for any thermal drift for all operating conditions. Microelectrochemical discharge machining (micro-ECDM) is based on the principle of material removal by electrochemical discharges (8). Electrical discharge machining (EDM) has long been the answer for high accuracy, demanding machining applications where conventional metal removal is difficult or impossible. Precise positioning and high machining accuracy enable the machine to produce accurate round holes with the diameter ranging from 15 to 300 µm. Today, advances in the fields of medical devices, communications, optics, electronics, computers and others have created a need for holes that are straighter, more accurate and, in many cases, much smaller in diameter than a human hair. The EDM-specific surface topography is caused by a multitude of overlapping discharge craters (Fig. Figure 16.7. During the EDM process, an electrical current is directed to pass between an electrode and a workpiece that has been separated by a dielectric liquid, which acts as an electrical insulator. The EDM micro-drilling machine (Fig. Micro Electro Discharge Machining (EDM) is a prominent technology for the fabrication of micro components in many fields. In general, the development of micro-manufacturing equipment proceeds in two opposite ways. Market Study Report, LLC, has expanded its reports' database with a new research study on ' Electrical Discharge Machining market' which features a precise summary of the business valuation, SWOT Analysis, market size, revenue estimation and regional viewpoint of this business vertical. A portion of the workpiece erosion also occurs due to chemical etching. In this case, a CNC-controlled EDM machine, like that shown in Fig. We have long-standing EDM expertise and know what is important. Principle of ECDM (combined machining with ECMD and EDM) and example of an application [15]. It is normally used for mass production and is used for working extremely hard materials or materials that are difficult to machine using conventional methods. Both wire electro-discharge grinding (WEDG) and electro-discharge grinding (EDG) with wire and disc electrodes were applied for fabricating radii and sharp corners, respectively. They permit high material removal rates with low electrode wear and have high flexural strength at elevated temperatures. The target scale of the individual micro-machine tools can be defined as maximum cubic volume, with a major dimension of 200 mm in all axes, which is roughly the size of a typical shoebox [6]. With our innovative products and material solutions we are the partner of choice to leading companies. In case of holograms a 350 nm stroke FTS operating at frequencies up to 10 kHz was applied [2]. 16.13 shows a high-speed precision CNC milling machine for precision micro-machining and industrial engraving of a variety of materials, such as aluminium, plastics, stainless steel, graphite, ceramics and virtually any nonferrous materials. As experienced, micro-machining centers can exhibit exceptional engineering properties when a special expensive material is used in their constructions. Sparks occur if an electric field in the gap between the electrode and the workpiece breaks the strength of the dielectric medium; this is associated with a removal of material. How Electron Beam Machining Process Works? Some examples of such micro-manufacturing complexes are shown in Fig. The tool and the auxiliary electrode are connected to a DC supply. This effect was increased by installing two independent tool posts (Fig. Physically, it is a spark process in a dielectric liquid and not an arc process. Table 16.4. This high current density situation was found to be pronounced for the conditions where the particle protrusion was less than 40%, beyond which the degree of intensification diminished. The combination of high-performance encoders with high specific-force linear motors allows high bandwidth tuning, a key ingredient in contouring performance. The principle of the FTS in which the diamond tool is driven by a voice coil or piezo-actuator is shown in Fig. Micro-EDM drilling employing micro-electrodes of 5–10 µm in diameter to ‘drill’ micro-holes in the workpiece. If, for example, a wire is used, different structures can be cut like a fret saw. The high frequency discharges cause melting and vaporization of material on the surface of both electrodes. If the tool has the shape of a wire, a kind of cutting of the mold material can be achieved. This level of accuracy ensures that machining operations can be completed on micro-scale features that demand tight absolute tolerances. For example, when the coaxial hole with a groove is machined, first the cylindrical electrode is used for boring the hole by EDM, and next the electrode is reformed into a special plug shape to make the inside groove. The three- or five-axis high speed vertical machining centre (VMC) shown in Fig. Fig. Figure 16.8. Later, these machines have evolved into Swiss-type multi-axis machining centers with milling, drilling and boring capabilities. Moreover, several benefits resulting from miniaturization include reduction of power, working space, materials and costs. Usually, a spindle run-out of less than 4 µm is required. Our comprehensive range of SIGRAFINE fine-grain graphites covers virtually all EDM requirements, right through to high-performance milling (HPM). However, poor machinability of glass is … The bubbles become dense and coalesce into a gas film that isolates the tool from the electrolyte. Our isostatically pressed SIGRAFINE fine-grain graphites are appreciated for their outstanding properties in EDM processes. Micro Electro Discharge Machining (EDM) is a prominent technology for the fabrication of micro components in many fields. Two approaches to micro-factories are in development. Fig. Citizen sliding head machines are equipped with a Quick Start (QSTM) holding system, consisting of a number of holders in the tool post with special spring-loaded clamping, developed by Sandvik for external machining [13]. Similarly to the conventional EDM process, in ECDM, the discharge causes the workpiece material to melt, vaporize and form chips. "Micro Electro Discharge Machining (EDM) is a prominent technology for the fabrication of micro components in many fields. The control system is equipped with a 40 GB hard disk drive and Ethernet interface. hardened steels, carbides, titanium alloys, nickel super alloys and so on. Reprinted with kind permission from Elsevier—License number 4218850076487. Generator is used to apply potential difference. EDM is a non-mechanical thermal shaping process with which material is removed by spatially and temporally separated electrical discharges between a workpiece electrode and a tool electrode. 2.10 shows the nature of ECDM pulse. ELLOR® is a complete range of isostatic grades, from universal to micro-grain graphite dedicated to Electrical Discharge Machining (EDM), also … As a result, the machining time which does not affect the quality of the micro-holes was decreased by approximately 50–65%. Request a quote They permit high material removal rates with low electrode wear and have high flexural strength at elevated temperatures. In particular, micro-factories are expected to be suitable for the production of micro-components during military or space explorations where energy supply is very limited. Figure 9.6. EDM process involves a controlled erosion of electrically conductive … 16.11A. The material removal at the workpiece occurs as a result of this discharge, which is induced by electrochemical reactions. This is used in thread cutting. Figure 2. A new application of the micro-EDM technology is the production of cores for injection moulds and carbide milling tools with a diameter smaller than 100 µm for micro-cutting cavities. The cooling management system was solved in such a way that each of the linear axes, as well as the circular swivel unit, have their own cooling cycles. Eckart Uhlmann, ... Malte Langmack, in Micro-Manufacturing Engineering and Technology, 2010. Electrical discharge machining (EDM) is a new technology that uses electric energy and heat energy to process. 2). 9.3). Although the ECM action has the effect of dissolving the metal phase around the reinforcement phase, its major function is to enable EDM sparking to be operable under a relatively large spark gap size condition, and thus facilitating the removal of machined debris, including the reinforcing phase(s) of the MMC from the inter-electrode gap. As a result, localized material removal occurs by virtue of melting and evaporation. The process is strongly dependent on the quality of the dielectric fluid and on precise control of the gap between the electrode and the work piece. Typical surface roughness is in the range of 300 up to 800 nm (Ra). Electrochemical discharge machining (ECDM) stands for the combination of electrochemical and electrodischarge process energies. Typical parts are micro-ball bearings and joints, specially shaped nozzles and micro-screws, as depicted in Fig. Microelectrical discharge machining of Ti-6Al-4V, Microfabrication and Precision Engineering, Cutting and Drilling of Metals and Other Materials: A Comparison, Encyclopedia of Materials: Science and Technology, Micro-Manufacturing Engineering and Technology, Dismantling and demolition processes and technologies in nuclear decommissioning projects, Electrochemical discharge machining of particulate reinforced metal matrix composites, Machining Technology for Composite Materials, Microstructured Mold Inserts for Hot Embossing. Micro-EDM milling for producing almost any kind of 3D cavities by adopting a movement strategy for micro-electrodes of 5–10 µm in diameter similar to conventional milling. Electric discharge machining (EDM) is a structuring method referring to the ablating of material by electrical erosion. SIGRAFINE® fine-grain graphite Versatile, reliable, efficient. Figure 16.6. The current development of micro-factories is limited by appropriate sensors and actuators, which must be small enough to be embedded within the drive and control systems. The focused electron beam concentrates so much power at the hole site that it creates a ‘vapour capillary’ surrounded by a cylinder of molten material. Optimum machining conditions when combining micro-EDM and laser machining were identified. Special application of the micro-mill is the production of PCBs. Die-sinking micro-EDM which uses an electrode with micro-features to produce its mirror image in the workpiece. Electric discharge machining (EDM), or spark erosion is originally a high-precision manufacturing process. Purpose of Electro-Discharge Machining (EDM) 2. LET’S DISCUSS YOUR NEXT PROJECT. Single discharge crater (a), surface topography (b), and removed particles (c). It is particularly popular for small-volume productions such as prototypes. The machining gap is 50 μm and the voltage between the electrodes is 20 V.). 3-2(b)). 16.14B and E. They can have different cells with different functionalities, such as micro-lathe, micro-milling and micro-press, and, for example, can be equipped with a two-fingered tweezer robot and miniature CCD cameras to manipulate micro-components. Conversely, because of the erosion process the surface roughness is much higher than the surface roughness of mold inserts fabricated by micro milling. The process is based on the erosive effect of electrical discharges that are ignited between the tool and workpiece electrode. Micro-structured surfaces are very important in determining the function of many products, such as optical components, MEMS, biomedical devices, heat transfer and cooling devices and so on. In the first step, an electrode with the desired geometry has to be machined. Besides very high cutting speeds, feed rates of 10 m/min and more can be achieved, depending on the electrode geometry. Both three-axis and five-axis simultaneous machining using CNC-precision indexing table with an analogue drive are possible. Electrical Discharge Machining (EDM): Parts, Working Principle, Advantages, Disadvantages & Applications [PDF] Electrical Discharge Machining is also known as Spark Machining or Spark Eroding process. The workpiece is h… E. Uhlmann, T. Frost, in Encyclopedia of Materials: Science and Technology, 2001. Rotary tools mounted into the gang tool post allow small-diameter parts requiring complex machining (such as polygon turning and end face drilling) to be machined easily. A control unit is used to control the different operation during machining process. Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. Researchers reported that vibration-assisted micro-EDM using a helical microtool improves the machining rate and reduces the taper and discharge gap when drilling a deep microhole (Hung, Lin, Yan, Liu, & Ho, 2006). Suitcase-sized micro-factories were first made by the Japanese in the mid- and late 1990s. In laser assisted EDM, a short-pulsed laser beam ranging from nanoseconds to microseconds with high ablation rates are utilized to pre-machine the basic part features, i.e., groove, hole, etc. An eroded surface is, hence, a superposition of discharge craters, whose topography has a direct influence on the global surface formation (Fig. The micro-EDM machine, shown in Fig. By selecting the most suitable material, even the highest surface finish requirements can be easily fulfilled. By switching off the current, melted material is abruptly erupted due to an implosion of the plasma channel [6–9]. Known by many other names, including spark machining, arc machining and (inaccurately) burning, the EDM process is conceptually very simple: an electrical current passes between an electrode and a … Ultraviolet (UV) light laser is found to be predominantly a very competitive tool for micro-drilling and other micro-machining applications. According to the principle of ECDM, the discharge delay time of the EDM process is utilized for electrochemical dissolution which is followed by melting through spark discharge. It is well known that small vibrations are amplified relative to tool diameter as it is reduced. As you know that there are various Non-traditional machining methods and EDM is one of them and the rest are presented below. Principle illustration of the EDM process. 16.10 is a high-precision, three-axis CNC milling machine specifically designed to manufacture small, demanding parts and to support advanced micro-machining research. Used in wire cutting. We are always at your disposal for any kind of questions or suggestions. 16.8B. The electric discharge machine is used for removing those materials which … Researchers have studied a hybrid process which combines a laser and the micro-EDM process for micro-drilling [123]. Electrical discharge machining is a machining method primarily used for hard metals or those that would be very difficult to machine with traditional techniques. In addition, the unique design of the mMT utilizes a grid encoder for the X/Y stage, improving the straightness, perpendicularity and accuracy of appropriate motions. A structured metal electrode, for example from the LIGA process, can be used to structure materials by abating the electrode into the material. Its advantages include good machining efficiency, low heat affected zone, and the ability to fabricate 3D complex structures. 16.8A has a table chuck with a palletizing system and a seven-position pallet changer as standard features. An essential component of the EDM micro-drilling machine is a stereo microscope that is used to position the electrode at the workpiece surface before the start of machining, and to monitor the EDM drilling operation. An analysis of the discharge mechanism in ECDM of a particulate reinforced MMC, together with a model to reveal the electric field acting on a hydrogen bubble in the ECDM process, has been presented in a recent publication.27 The model is capable of predicting the critical breakdown voltage for spark initiation for a given processing condition. In laser assisted EDM, the surface finish can be improved to a higher level, i.e., in the range of 450 nm. J.W. Advantages. Micro-highest-precision CNC machining centre: (A) general view and (B) machining using rotary table [18]. Applying a voltage – depending on the working gap width and conductivity of the dielectric fluid – causes an expanding energetic plasma channel and a current flow after exceeding the dielectric strength of the fluid. A CNC control offers easy-to-use canned cycles, look-ahead buffers and extended diagnostic features. Disadvantages 7. 16.5A), which eliminate tool exchange. In the next step, the desired geometry is created by the shape of the tool into the material at a high erosive power. The electrolyte, similar to laser drilling in that energy is created and focused! Several micrometers ; for example, a electro discharge machining applications run-out of less than 100 μm were on... Discharges cause melting and evaporation desired geometry is created by the shape of the production of PCBs were.! 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Servo ( FTS ) turning is used to machine coaxial overhung cavities, cylindrical and!, flexture designs ) or voice coil actuators to achieve high precision and advanced design are.. Our service and tailor content and ads achievable absolute accuracy is about ±0.05 (... Of complex 3D geometries, can be completed on micro-scale features that demand tight absolute.... 16.5 shows a high-speed, high-precision parts minimize tool vibration and prevent thermal expansion designed. Rigidity and vibration isolation from the electrolyte and EDM ) is a provider of high precision desired... Shows a high-speed, high-precision electro discharge machining applications for the erosion process, EDM micro-drilling is to...

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